A base station under the cloud-radio access network (C-RAN) architecture is generally formed by two parts: namely, a remote station and a central station. The remote station includes a radio unit (RU), and is responsible for sending data to and receiving data from a user equipment (UE). The central station is a base band unit (BBU), and is responsible for processing and maintaining data received and sent by the remote station. The RU is installed nearby an antenna, the BBU is installed in a telecommunications room, and usually the two are connected through an optical fiber, and implement data communication through a common public radio interface (CPRI) protocol or other protocols. The RU and the BBU are geographically separated, and BBU is centrally placed. A multi-site RU can share a BBU resource, and can simplify originally distributed maintenance work to the side of the central station, thereby saving space and reducing setting cost.
At present, in the third generation communication technology (3G) network, the distributed base station architecture shown in FIG. 1 is used massively. In FIG. 1, the RU is connected to a digital unit (DU) through a routing device. Usually, one DU can be connected to RUs of a plurality of base stations to serve as a BBU shared by the plurality of base stations. The routing device is responsible for transmitting uplink data based on the CPRI protocol of one RU (CPRI data) to a DU, or transmitting downlink CPRI data of a DU to an RU. A plurality of DUs form a DU network (DU Cloud). In DU Cloud, DUs implement CPRI data exchanging through a DU switching unit (DU Switch). The DU cloud serves as a baseband resource pool for a plurality of base stations and processes and maintains CPRI data of each base station RU.
In the foregoing data transmission process, the inventor finds that the prior art at least has the following problems: usually, an RU includes a single-standard RU and a multi-standard RU, where the single-standard RU transmits CPRI data of one standard to the DU, and the multi-standard RU can transmit CPRI data of multiple standards to the DU simultaneously. When multi-DU tightly coupled coordination (such as coordinated multi-point transmission and reception technology (CoMP) is performed, if the multi-standard RU transmits CPRI data of multiple standards to the DUs simultaneously, CPRI data of different standards may be received by one DU if routing is only performed according to a routing relationship between an RU and a DU. Because each DU may only process CPRI data of one standard or multiple standards, the DUs need to exchange CPRI data of different standards through a DU Switch, so that CPRI data of these standards can be processed. For example, after receiving first standard CPRI data and second standard CPRI data, a DU for processing first standard CPRI data only processes the first standard CPRI data, and transmits the second standard CPRI data to a DU for processing second standard CPRI data. Frequent data transmission between the DUs increases data exchange traffic in the DU Cloud, and increases a resource burden of the DU Cloud.